622 THE PEOPLE'S FARM AND STOCK CYCLOPEDIA. 



The foot consists of three distinct parts : 1. The external 

 wall or crust. 2. The sole. 3. The frog. 



The CRUST reaches from the hairy skin to the bottom of the 

 foot, averaging about three and a half inches, with a thickness 

 of about a quarter of an inch, having horny fibers running par- 

 allel from skin to bottom of foot. 



The SOLE is a horny plate at the bottom of the foot, which 

 should be slightly coRcave. It is usually about one sixth of 

 an inch thick, but varies, like the wall, in different horses. It 

 is thicker where it runs back between the bars and the crust. 



The FROG is the elastic triangular, horny cushion, filling the 

 space between the heels, and placed directly under the navicu- 

 lar bone. 



The crust and sole and frog are all fibrous. The crust is 

 like whale-bone, the sole rather separating into scales ; while the 

 frog has finer fibers and a larger portion of gelatine, which 

 keeps it soft and more elastic. 



The hoof is developed by secretions from the blood, sup- 

 plied by small vessels or villi at the coronet. The growth of the 

 hoof lengthwise is constant, to make repairs or to make good 

 the natural wear of the foot of the horse unshod. The weight 

 of the horse does not mainly rest on the sole of the foot, but 

 mostly on the coronary ligaments. So the weight is direct on 

 the horny or whale-bone part. The elasticity of all the solid 

 parts and of the coronary ligaments afford protection and 

 relief from the shock of a blow of the foot on hard roads or 

 paved streets. This elasticity should never be lessened by 

 cutting away of part of the frog, as do many farriers, when 

 preparing the foot for the shoe. Cutting the frog not only 

 lessens it, but causes it to harden. ^ There is no reason favor- 

 ing the trimming of the frog, as of the crust, because its con- 

 stant contact with the ground or floor, and its softer nature, 

 cause it to wear away sufficiently. 



Stonehenge closes his chapter on the foot with the following: 

 " It will thus be seen that the foot of the horse is a most com- 

 plex structure, which is liable to derangement whenever the 

 hoof or horny case is interfered with, and this may occur either 



